A106872 Primes of the form 2x^2+xy+4y^2.

2, 5, 7, 19, 41, 59, 71, 97, 101, 103, 107, 109, 113, 157, 163, 191, 193, 211, 233, 257, 281, 307, 311, 317, 359, 373, 397, 419, 421, 439, 443, 467, 479, 503, 541, 547, 563, 593, 599, 659, 661, 683, 691, 701, 727, 733, 751, 769, 877, 887, 907, 977, 997, 1033

Offset: 1

Author

T. D. Noe, May 09 2005

Keywords

• nonn
• easy

Comments

Discriminant=-31.

Primes p such that the polynomial x^3-x^2-1 is irreducible over Zp. The polynomial discriminant is also -31. - T. D. Noe, May 13 2005

Links

• Vincenzo Librandi and Ray Chandler, Table of n, a(n) for n = 1..10000 [First 1000 terms from Vincenzo Librandi]
• N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)

Crossrefs

Primes in A123064.

Programs

Mathematica

Union[QuadPrimes2[2, 1, 4, 10000], QuadPrimes2[2, -1, 4, 10000]] (* see A106856 *)